Employees in Beijing are wearing gas-mask style protective headgear at their desks as residents across northern China battled through choking pollution.

Air quality levels rose above index limits in Beijing in the wake of warnings that the smog may not clear until Thursday.

Visibility was reduced to around 200 metres in the centre of the capital, where mask-wearing pedestrians made their way through a murky haze, despite warnings from authorities to stay indoors.

In a Beijing city office visited by a France-based news agency, up to 20 workers wore the protective headgear at their desks, and the cloud of pollution shrouded large swathes of the country for the second consecutive day, the Telegraph reports.

According to the paper, state broadcaster China Central Television (CCTV) showed vehicles using full headlights in mid-morning to light a way through the smog, mainly in the badly affected central province of Henan.

A total of 109 flights were cancelled at Zhengzhou Airport in Henan, said CCTV, adding that the haze would last until Thursday, the paper added. (ANI)